Locking hinge



April 29, 1952 c. c. BAKER 2,594,583

LOCKING HINGE Filed Jan. 5, 1950 3 Sheets-Sheet 1 iwmw g I "II T Z Q I III/1171110 HI 5M l O V/// //w INVENTOR. 3 CRAIG C. BAKER ATTORNEY April 29, 1952 c, c, BAKER 2,594,533

LOCKING HINGE 3-Sheets-Shet 2 Filed Jan. 3', 1950 25 24 "IJ /.-7-'/'-' I igs L7 2 i? n 2 so IN VEN TOR.

CRAIG C. BAKER 5?? Q1] ATTORNEY IIIII/IIIIIIIIII/IM Ap 29, 1952' c. c. BAKER 2,594,533

LOCKING HINGE Filed Jan. 3, 1950 3 Sheets-Sheet 3 INVENTOR.

CRAIG C. BA KE R ATTORNEY Patented Apr. 29, 1952 UNITED :S TATF ES PATENT O FF I CE IZIzOGKING HINGE Graig CIBaker, Los'Angeles, Calif.

Application January 3, 1950, Serial No. 136,530

6 Claims. 1

This invention relates in vgeneral ito :ahmge 'of the type capable :not :only .oiserving in the usual capacity asa'hingebut'also of being l'ocked in a desired, predetermined position, :fandithus of holding the hingedly-connected members :in locked desiredposition with respect-'toeachother.

More specifically this invention relates to a hinge adapted to connect one member :to another or to connect :one member 2130 its-support,

for limited pivotalmovement, but in such -manner that themembercan'be locked-in-=-extended or predetermined position with respect to the other member or support by the hinge, and nevertheless, when not -so locked, man have pivotal or .hinged movement with-respect to the other member or support.

An object of the invention is to provide an improved hinge which'will automaticallybecome locked when the hinged parts are swung to an opened or predetermined position'with respect to each other.

Another object of this invention :is to-provide an. improved locking hinge of the'type above .indicated which can be'quickly and'easilylunlocked by a simple manual operation.

An additional and important-objectof-theinvention is to provide a locking hinge w hich -will hold the hinged parts firmly-in the-desired or predetermined locked position and which will continue to do so regardlessof-any-.0rdinary wear of any parts of the hinge or locking elements.

A'further objectof this invention is to .provide an improved locking hinge which will lie-practical and simple in construction, convenient in size, inexpensive to manufacture, and capable of use in a variety of structures. 7

The invention resides in the novel-construction of the parts and -elements, and in their special combination I andarrangement, as hereinafter described. In the following descrip'tion,

reference is madeto theaccompanying drawings, in which: a

Fig, 1 is aside elevationofone-formoimy locking hinge showing the same .inmaximum open locked position; v

Fig. 2 is a similar side elevation .showing-Lthe same in partly open unlocked-position;

Fig. .3is a'bottom plan viewof .the-openllocked hinge, taken on .line-l3--3 of Fig. "1,. but drawn to a slightly larger scale, and. illustrating 1 the manner in which myhinge, when maderinthis particular form, .is manually unlocked;

Fig.4 is a sectional elevation.oftheiopen locked hinge taken on line 4- 4 of.Fig.'3;

Fig. 5 is a fragmentary-sectional..plan .v'iew showing'one end of the hinge pivotpin; A

Fig. 6 is a bottomplan view, similar to Fig.

3, but'ishowing a modified form in whichmy hin'ge ma'y bemadeandshowing the hinge also inropenilocked position;

Fig. 7 is a sectional elevation'on line 1-1 of Fig. '8 vis .a similar sectional elevation illus- :-Fig.-"-9 is a corresponding sectional elevation .showing the hinge-in-completely closed unlocked position;

Fig. 10 :is a further corresponding sectional elevationshowing the hinge-moving back towards fully opened position;

Fig. 11 is a fragmentary-sectional plan View 'showin'g'one end of the hingepin and-adjacent members;

.-Fig. 12 "is a plan view-of a further modified iform in which my hinge maybe made, theview beingtaken on line l2-.l2 of.-Fig. 13; and

Fig. 13 is a sectionalelevation on line 13-43 of Fig. 12 and illustrating the manner in which this form of my hinge is manually unlocked.

'Referringfirst to Figs..1-'5 inclusive, thereference characters It) and H indicate ingeneral twomembers which are connected together by means -of the hinge. .includestwo pairs of spaced metal hinge elements The locking hinge itself l2,- l2 and [3, I3 each .pairbeing joined byjthe .integral cross webs Mand l5 respectively, each pair of elements and connecting web constituting one wing of the hinge and the two wings being-.securedto the 'two members i0 andll frespectively.

The connected pair .of hinge elements 13, 13

.are so spaced that they extend inside of the hinge elements l2, 12 as shown in Fig. 3. 'The adjacent overlapping inner ends of these 'elementsare circular in shape, these circular por- .tions being designated by the reference characters 12, I2 and I3',l3 respectively and these circular. registering portionsare pivotally mount- -,edon a common hinge pin or axial shaft 16.

Each end of theshaft i'fi'has 'a portion ll (Fig. 5) of smaller diameter on which the elements I 2,v I2 and 13, [3 are pivotally mounted, "and broadheaded screws l8, securedin threaded remodate a pair of wedge-shaped locking blocks 20 and 2| which extend transversely across the two pairs of elements in the relative positions shown in Figs. 1 to 4 and with their ends extended a short distance beyond the outward faces of the circular portions I2, I2 as shown in Fig. 3. These locking blocks 20 and 2| are connected by a pair of coil springs 22 (Figs. 3 and 4) which extend around the shaft or hinge pin l6 and thus tend to pull the locking blocks towards each other and keep them from dropping out of the device.

When the hinge elements I2, I2 and I3, I3 are moved so that the members If! and II to which they are attached are arranged at an angle of 180 with each other, and thus when the hinge is in fully opened position illustrated in Figs. 1 and 4, the two pairs of cut-out sections I9 of the portions I2, I2 will be in registration with the corresponding parts of cut-out sections respectively, in the portions I3, I3 and consequently the locking blocks 20 and 2| will be pulled by their springs into these registering cutout sections, as illustrated in Figs. 1, 3 and 4. When the locked blocks 2|) and 2| are in such position the hinge is in open locked position.

To unlock the hinge, the operatortakes a looking block between a thumb and forefinger of each hand and pulls the blocks slightly apart until both blocks are moved out of the cut-out sections I9. Then the hinge elements are free to rotate with respect to each other to a maximum of 180, and when the pairs of cut-out sections are moved out of registration the locking blocks 2!] and 2| will remain in their outward unlocked position bearing against the peripheries of the circular portions I2, I2 and I3, I3.

My hinge as thus far described might be used, for example, in attaching a drop leaf to a table. Thus when the drop leaf is swung up to horizontal position the hinge automatically locks and serves to hold the drop leaf in raised horizontal position until it is unlocked in the manner illustrated in Fig. 3.

It would also be possible to arrange the pairs of cut-out sections I9 of the circular portions I2, I2 and I3, I3 at a spaced interval of 90 instead of 180 when it is desired to have the two members l and. I I locked at right angles to each other. Thus, as a further example, in this manner my hinge could be used for attaching a drop shelf to a vertical wall or a folding leg to a table top.

As previously mentioned, and as shown in the drawings, the locking blocks 20 and 2| are wedgeshaped and the cut-out sections I9 are similarly shaped for proper engagement with the locking blocks. There is a particular advantage in having the locking blocks and the related cut-out sections wedge-shaped, for not only is the entry of the locking blocks into the cut-out sections facilitated, but the force exerted on the locking blocks by the springs, wedging the blocks into the cut-out sections to the fullest extent possible, also results in the hinge being firmly locked with all possibility of play in the locked sections eliminated. In other words, if the cut-out portions are properly formed the locking hinge becomes in a measure self-tightening, for ordinary wear of the locking blocks or of the opposed edges of the cut-out portions, or even of the hinge shaft will not result in any play in the hinge sections when locked. This feature, as apparent, is of particular importance, for example, when the locking hinge is used for attaching a folding leg to a table top, for in such construction the slightest amount of play in the locked elements would be sufiicient to render the table leg wabbly or unsteady unless provided with separate bracing.

Another incidental advantage in the hinge as thus far described is the fact that the portions I2, I2 and the corresponding portions I3, I3 of the hinge elements have circular peripheries which move in the same orbits during movements of the hinge and their cut-out sections come into registration only when in looking position when engaged by the locking blocks. This prevents the possibility of any article or portion of material inadvertently catching on these hinge elements or being subjected to any scissor-like or pinching action when coming into contact with any part of the hinge in operation.

In the modified form of my invention illustrated in Figs. 6-11 inclusive the pairs of hinge elements 23, 23 and 24, 24 are similar to the elements I2, I2 and I3, I3 respectively, in the preceding figures and have the corresponding circular portions 23, 23 and 24', 24', with pairs of cut-out sections 25 similar to the cut-out sections I9 and similarly arranged. Also a pair of locking blocks 26 and 21 are similarly provided for locking engagement with the pairs of cut-out sections 25 when these are brought into registration respectively, the locking blocks 26 and 2'! being connected by a pair of coil springs 28 and 29 in the manner previously described.

To facilitate the moving of the locking blocks 26 and 21 out into unlocked position, I provide a pair of specially shaped discs 30 and 3|, rotatably mounted on the hinge pivot shaft 32 and positioned inside of the inner circular portions 24', 24' of the hinge elements respectively, as shown in Fig. 6. A coil spring 33 on the pivot shaft 32 holds the discs 30 and 3| against the circular portions 24, 24' of the hinge elements. The rotatable discs 30 and 3| are identical in shape and the shape of the disc 30 is clearly shown in Figs. 7-10 inclusive. Thus each disc 30 and 3| has a pair of similar, oppositely arranged, cutout portions 34 and 35, each cut-out portion being formed so as to present one outwardly-extending substantially straight edge 36 and another outwardly leading curved cam-like edge 31. Each disc 30 and 3| also has a peripheral extension'or finger lug 38 (Fig. 6) extending inwardly to enable the discs to be rotated in unison (in clockwise direction as viewed in Figs. 7 and 8) by the finger of the operator in the manner illustrated'in Fig. 8.

When the hinge is in the fully opened and locked position indicated in Fig. 7, slight manual rotation of the pair of unlocking discs 30 and 3| (thus clockwise as illustrated in Fig. 8) will move the locking blocks 26 and 21 out of locking engagement with the pairs of cut-out sections 25 and thus permit the two unlocked hinged portions to be rotated with respect to each other and towards each other until the hinge finally reaches the fully closed position illustrated in Fig. 9.

Due to the outward pressure exerted against both discs 30 and 3| by the coil spring 33, causing these discs to have moderate frictional engagement with the adjacent circular portions 24', 24' respectively of the inner hinge element 24, the rotation of the hinge element 24 with respect to the hinge element 23 will tend to cause further rotation (in clockwise direction as viewed in Figs. 8 and 9) of the discs 3|! and 3|. Rotation of the discs 30 and 3| in this direction, however, is limited by a central, inwardly-extending lip 39 on the locking block 2 6, which, 'while the locking block 26 is in unlocked positionfis adapted to 'engage the fingerlugs -38 of the discs 3ll and 3 l to limit suchrotation. The-purpose of this is to prevent the discs 3 "and-'3 I being rotatedto such extent in that-direction (clockwise) as 'to bring them out of unlocking engagement with the locking blockslfi and- 21, sincethis might resultin the lockingofthe hinge insome-other position than the fully opened position or predetermined position for locking. -Similar1y,'when rotation'o'f the hinge elementsin opposite direction withrespect to each-other (forexample, whenhinge element 24 is moved counterclockwise from the position in Fig. 9 to the position of Fig. l fi and 'finally to the fully opene'd pos'ition of -Fig."7) it is necessary to' limit the' rotationof the discs i and 3 l in the correspondingopposite direction 1.50 -that these discs willrcontinue to haveunlocking engagementwith the locking V blocks until .thehinge is moved to --the desired 1 predetermined or fully opened position. 'Theperimetersof each of the discs 3ll and 3l accordingly hasia'shoulder 50 extending a slight distance radially beyond the perimeters of the-circular portions of the hinge elements and'adapted to engage the locking block ZB' When this locking block is-in unlocked position, asillustrated. in-F'ig. 10', to limitrotation of the discs 3fl'and 3l intheopposite (counterclockwise) direction.

Thus when the-hinge. is in open locked position, as illustrated in Fig. -'7, aslight manual rotation of-the discs-'30 and3l by the-finger ofthe operator-(clockwise as viewedin Fig. 8) will unlock the lhingegandthe'hinge will then remain unlocked in all positions to Which'the hinge elements are move'd until the hinge .is'a'gain returned to the fully :opened position, whereupon it will automatically-again become locked.

In the -furthermodi'fied form of my locking hinge illustrated inFigs. 12 and 13, only one locking block is employed. The hinge elements and 4| have similarlpairs of circular portions 40,

40' and 4l', 4l respectively-butthe circular portions-4l", 4l of the hinge element 4| are of smaller diameter than the circular portions 40,

40'. In'this modified'form a'pair of cut-out sections is provided in the inner circular portions 4|, 4l-'only, and the singlelocking'block'43 is adapted to engage the cut-out sections of these inner circular portions 4 l '54! when the hinge is in 'tully'opened position, but the lockingblock "43 does not'extend to the outer circular portions 40540. Under some conditions it may be preferablenot to have the locking'block extendingbeyond the sides of the hinge if the extending'ends of the block would be likelyto catch on any material or object.

In' this construction the locking block 43 slides on a portion o'f the cross web of the hinge element 4U, and, like the locking blocks previously 'block'43, extend past the hinge shaft'and have the other ends attached to the-Web of the other hinge element M. An upstanding finger lug 44 is mounted on-a rear extension of the locking block to enable the locking block to be easily -mcved out of locking position" by the finger of the operator; as illustrated in Fig. '13. The circular portions 4 l '4 I each have a projecting shoulder 45 adjacent thecut-out seotion and adapted to engage the undersideiof the web of the hinge element-4 9 when the hinge is swung to fully opened position was to preventlthe'hingemembersfrem moving beyond-thefully opened position regardless of the position of the locking block 43. -'As.apparent, inthis modified form my locking hinge "also functions in substantially the same way as previously described, that is to say, when the'.hinge is swung toa .predetermined oriully opened position the hinge will automatically :become locked; slight finger manipulation of the lockingblock unlocks the hinge and. permits the hinge to be moved .to closedior partly closedposition; and the I hinge will not look at :any other position than the desired or fully opened position. Obviously'my. locking hinge when made in any of the forms which I have illustrated and vdescribed'can be employed in various uses including thoseindicatedatlthe beginning ofithis specification. 7 Further minor modifications might .be made in the construction of my clocking .hinge without departing "from the: principle of 1 my :in-

vention. .For example, the springs'for exerting the force necessaryto :move thelocking blockfor blocks into, locking and tightening position in the cut-rout sections could be differently arranged or :diiferently mounted. However the preferred examples of the waysin whichmy invention may be carried out I consider to be those whichI chingei'elements constituting the other wingzofi-the hinge,'...both .pairs'of said elements havingcircular portions oconcentrically mounted on a common hingeLpin, the circular portions ofcsaid first mentioned: pair iof elements positioned adjacent the insideitfacesof theicircular portions ofosaid second mentioned pair 'of elements respectively, :identical, itransversely-aligned wcut-out sections in the perimeters 01 .the circular portions .of said pairs of elements, a transversely-extending :lockin block of wedge-shaped cross: section :mounted on one :Wing of said hinge in contact with 'the perimeters of said circular portions of said elements and adapted for engagement with ;said

cut-out sections, said out-out sections :so located on the perimeters of the. circular portions of .said pairs of elements that said sections will .beiin registration with said locking block when .said

hinge-is opened to a predetermined desirediposi- "tion, a pair of coil springs'having one end attac hed to'said locking block and the other end attached on the other-wing of said hinge extendin-g across said hinge past said hinge'pin and exertingaforce to pull said locking block inwardly 'towardssaid hinge pin, whereby when said hinge iscopened to said desired position said locking "block will be autornaticallypulled by said springs into -said cut-out sections to lock said hinge in said' po'sition.

2."In=a hinge of the character describedya pair ofsp aced'parallel hinge elements.constitutingione wing of the hinge, a second pair of identical spaced hinge elements constituting the other wing 'o'f the hinge, bothpairs of said elements -having circular portions of the same diameter concentricallymounted on a commonhingelpin, the circular portionsof said first mentioned pair of elements positioned adjacent the inside faces ofthe circular portionsfofsaid second mentioned pair of elements respectively,'pairs of identical, transversely- -aligned cut-out :sections in the perimeters of the circular portions of said pairs of elements, a pair of transversely-extending locking blocks of wedge-shaped cross section mounted on the respective wings of said hinge in contact with the perimeters of said circular portions of said elements and adapted for engagement with said pairs of cut-out sections respectively, said cut-out sections so located on the perimeters of the circular portions of said pairs of elements that said sections will be in registration with said locking blocks when said hinge is opened to a predetermined desired position, a pair of coil springs connecting said locking blocks extending across said hinge past said hinge pin and exerting a force to pull said locking blocks inwardly towards said hinge pin, whereby when said hinge is opened to said desired position said locking blocks will be automatically pulled by said springs into said pairs of cut-out sections respectively to lock said hinge in said position.

3. A hinge of the character described including a pair of spaced parallel hinge elements constituting one wing of the hinge, a second pair of similar spaced hinge elements constituting the other wing of the hinge, both pairs of said elements having circular portions of the same diameter concentrically mounted on a common hinge pin, the circular portions of said first mentioned pair of elements positioned adjacent the inside faces of the circular portions of said second mentioned pair of elements respectively, pairs of identical, transversely-aligned cut-out sections in the perimeters of the circular portions of said pairs of elements, a pair of transversely-extending locking blocks of wedge-shaped cross section mounted on the respective wings of said hinge in contact with the perimeters of said circular portions of said elements and adapted for engagement with said pairs of cut-out sections respectively, said cut-out sections so located on the perimeters of the circular portions of said pairs of elements that said sections will be in registration with said locking blocks when said hinge is opened to a predetermined desired position, a pair of coil springs connecting said locking blocks extending across said hinge past said hinge pin and exerting a force to pull said locking blocks inwardly towards said hinge pin, whereby when said hinge is opened to said desired position said locking blocks will be automatically pulled by said springs into said pairs of cut-out sections respectively to lock said hinge in said position, a pair of unlocking discs mounted on said hinge pin adjacent the inside faces of the circular portions respectively of said first mentioned pair of elements, each of said discs having peripheral cam edges adapted to engage said blocks when said discs are rotated in one direction, whereby to move said blocks out of locking engagement with said cutout sections, a spring mounted on said hinge pin and pressing outwardly against said discs where-.

by to tend to cause said discs to rotate with said first mentioned elements, means limiting the rotation of said disc, whereby to prevent inadvertent interference by said discs with the looking action of said blocks.

4. A hinge of the character described comprising a pair of spaced parallel hinge elements constituting one wing of the hinge, a second pair of identical spaced hinge elements constituting the other wing of the hinge, both pairs of said elements having circular portions of the same diameter'concentrically mounted on a common hinge pin, the circular portions of said first mentioned pair of elements positioned adjacent the inside faces of the circular portions of said second mentioned pair of elements respectively, pairs of identical, transversely-aligned cut-out sections in the perimeters of the circular portions of said pairs of elements, a pair of transversely-extending locking blocks of wedge-shaped cross section monuted on the respective wings of said hinge in contact with the perimeters of said circular portions of said elements at diametrically opposite points and adapted for engagement with said pairs of cut-out sections respectively, said cutout sections so located on the perimeters of the circular portions of said pairs of elements that said sections will be in registration with said locking blocks when said hinge is fully opened, a pair of coil springs connecting said locking blocks extending across said hinge past said hinge pin and exerting a force to pull said locking blocks inwardly towards said hinge pin, whereby when said hinge is fully opened said locking blocks will be automatically pulled by said springs into said pairs of cut-out sections respectively to lock said hinge in fully opened position, a pair of unlocking discs mounted on said hinge pin adjacent the inside faces of the circular portions respectively of said first mentioned pair of elements, each of said discs having peripheral cam edges adapted to engage said blocks when said discs are rotated in one direction whereby to move said blocks out of locking engagement with said cut-out sections, finger lugs on said discs to facilitate the manual rotation of said discs, a spring mounted on said hinge pin and pressing outwardly against said discs whereby to tend to cause said discs to rotate with said first mentioned elements, an engaging element on one of said blocks for engaging said finger lugs to limit the rotation of said discs in one direction, and means limiting the rotation of said discs in the opposite direc tion, whereby to prevent inadvertent interference by said discs with the locking action of said blocks.

5. In a hinge, a pair of spaced parallel hinge elements constituting one wing of the hinge, a second pair of similar spaced hinge elements constituting the other wing of the hinge, both pairs of said elements having circular portions concentrically mounted on a common hinge pin, the circular portions of said first mentioned pair of elements positioned adjacent the inside faces of the circular portions of said second mentioned pair of elements respectively, a pair of identical, transversely-aligned cut-out sections in the perimeters of the circular portions of said first mentioned pair of elements, a transversely-extending locking block of wedge-shaped cross section mounted on one wing of said hinge in contact with the perimeters of said circular portions of said first mentioned pair of elements and adapted for engagement with said pair of cut-out sections, said cut-out sections so located on the perimeters of the circular portions of said first mentioned pair of elements that said sections will be in registration with said locking block when said hinge is opened to a predetermined desired position, spring means connected with said locking block and constantly exerting a force to move said locking block inwardly towards said hinge pin, a pair of unlocking discs mounted on said hinge pin adjacent the inside faces of the circular portions respectively of said first mentioned pair of elements, each of said discs having a peripheral cam edge adapted to engage said block when said discs are rotated in one direction, whereby to move said block out of locking engagement with said cut-out sections.

6. In a hinge of the character described, a pair of spaced parallel hinge elements constituting one wing of the hinge, a second pair of similar spaced hinge elements constituting the other wing of the hinge, both pairs of said elements having circular portions of the same diameter concentrically mounted on a common hinge pin, the circular portions of said first mentioned pair of elements positioned adjacent the inside faces of the circular portions of said second mentioned pair of elements respectively, pairs of identical, transversely-aligned cut-out sections in the perimeters of the circular portions of said pairs of elements, a pair of transversely-extending locking blocks of wedge-shaped cross section mounted on the respective wings of said hinge in contact with the perimeters of said circular portions of said elements and adapted for engagement with said pairs of cut-out sections respectively, said cut-out sections so located on the perimeters of the circular portions of said pairs of elements that said sections will be in registration with said locking blocks when said hinge is opened to a predetermined desired position, spring means 10 connected with said locking blocks and constantly exerting a force to move said locking blocks inwardly towards said hinge pin, a pair of unlocking discs mounted on said hinge pin adjacent the inside faces of the circular portions respectively of said first mentioned pair of elements, each of said discs having peripheral cam edges adapted to engage said blocks when said discs are rotated in one direction, whereby to move said blocks out of locking engagement with said cutout sections, and fingerlugs on said discs to facilitate the manual rotation of said discs.

CRAIG C. BAKER.

REFEBENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 283,128 Masters Aug. 14, 1883 1,226,324 Gage May 15, 1917 1,530,116 Hawkins Mar. 1'7, 1925 1,618,885 Minor Feb. 22, 1927 

